When the Northern California ACLU branch tested the system by running photographs of every member of Congress through the system and comparing them with a database of 25,000 mugshots, 28 false matches reportedly came through.(Photo: Dreamstime/TNS)

The confidence thresholds are different for objects than they are for people, Amazon Web Services said in a statement.

"While 80 percent confidence is an acceptable threshold for photos of hot dogs, chairs, animals or other social media use cases, it wouldn’t be appropriate for identifying individuals with a reasonable level of certainty," according to the statement.

Amazon recommends that when using the technology for law enforcement activities, like facial recognition, customers should set a threshold of at least 95 percent.

The program is intended to be used by matching footage from body cameras or CCTV devices with mugshot databases, allowing law enforcement to identify suspects more easily to prevent crimes, including human trafficking, child exploitation and package theft.

In real world scenarios, Amazon said in the statement that the Rekognition software is used to help narrow the field so humans can consider options using their judgment, rather than relying on the technology to make the decisions.

"We remain excited about how image and video analysis can be a driver for good in the world, including in the public sector and law enforcement," according to the statement.

But, civil rights activists worry that the system could turn out inaccurate result.

When the Northern California ACLU branch tested the system by running photographs of every member of Congress through the system and comparing them with a database of 25,000 mugshots, 28 false matches reportedly came through.

While the incorrect flags included people of every party, gender, age and race, they disproportionately targeted people of color, the ACLU said. Only 20 percent of Congress is made up by people of color, but they represented 39 percent of the false matches.

Among those falsely flagged by the system was Rep. John Lewis, D-Ga, the legendary civil rights activist. Five other members of the Congressional Black Caucus were incorrectly matched.

"These results demonstrate why Congress should join the ACLU in calling for a moratorium on law enforcement use of face surveillance," the ACLU said.

Here's the full list of members of Congress incorrectly matched with mugshots: